Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e520fc4bb3f155fa690337840125a69ace1a6a7dc29c701f5d99b35645ca3ac' 
  AND token = 'fL3yfZ96ElYyk0tPz1YiA+TNuo5+mYLqEv/OEaNwtBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}